66691611 has 12 divisors (see below), whose sum is σ = 110094192. Its totient is φ = 38109456.

The previous prime is 66691609. The next prime is 66691621. The reversal of 66691611 is 11619666.

It is not a de Polignac number, because 66691611 - 2¹ = 66691609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66691621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 529236 + ... + 529361.

It is an arithmetic number, because the mean of its divisors is an integer number (9174516).

Almost surely, 2^66691611 is an apocalyptic number.

66691611 is a deficient number, since it is larger than the sum of its proper divisors (43402581).

66691611 is a wasteful number, since it uses less digits than its factorization.

66691611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058610 (or 1058607 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 66691611 is about 8166.4931886337. The cubic root of 66691611 is about 405.5306988901.

The spelling of 66691611 in words is "sixty-six million, six hundred ninety-one thousand, six hundred eleven".